Intermittent BSODs

Hey, I bought my computer and built it about a year ago.
And from the start BSODs started and I cant figure out why !
Mostly it happens when I play games and listening to music also when I have like youtube song on and tab in/out from a game it usally BSODs.

There is also this APPCRASHES all the time on my comp, every game I play crashes at least 2 times a day, sometimes without a crashfile.

Memory or hard drive... Did you run Memtest86 for 7 passes? Test the hard drive by going to Computer, right-click on the C drive. Select Properties, Tools, check now. Put a check mark in both boxes to set a disk check on the next start up. This will take some time... If there are any new BSOD's post them